The article uses "best" and "senior" as well, more often than "famous", and explains that the data refers to times when "the senior cardiologists were out of to

The article uses "best" and "senior" as well, more often than "famous", and explains that the data refers to times when "the senior cardiologists were out of town" (anyone attending conventions, for example.) It's unlikely there are enough "famous" cardiologists alone to have accounted for "tens of thousands" of admissions. If so, the meaning of "famous" is downgraded to those who are sufficiently senior, rather than how we usually think of "famous."